Functional connectivity profile of the amygdala subfields associates with emotional well-being in aging

Amygdala-related functional connectivity plays a crucial role in human emotion, cognition, and mental well-being. The amygdala is a highly heterogeneous structure, with subregions that have both distinct and overlapping functions. However, the connectivity patterns of different amygdala subregions--and how these associations vary with age--remain poorly understood. Functional MRI data were analyzed from 68 younger adults and 66 older adults during movie watching in a 7T MRI scanner. Partial least squares (PLS) analysis was used to identify latent variables capturing variance associated with age-related differences in the functional connectivity patterns of three amygdala subregions: the basolateral (BLA), centromedial (CMA), and superficial (SFA) nuclei. In addition, covariance between behavioral measures, such as emotional resilience and cognitive function, and functional connectivity of these subregions was examined. We further explored the associated cognitive processes, correspondence with large-scale brain networks, and the underlying chemoarchitecture of the identified connectivity patterns of the BLA, CMA, and SFA. Multivariate analyses revealed age-related and subregion-specific functional connectivity patterns. Functional connectivity patterns of amygdala subregions were further associated with emotional resilience, which largely overlapped across widespread brain regions; however, their associations differed by age. Stronger coupling of amygdala subregions predicted higher resilience in older adults but lower resilience in younger adults. The identified connectivity patterns were linked to the salience, control, and default mode networks and showed spatial correspondence with mGluR5 and 5-HT6 receptor distributions. These findings highlight age-dependent reorganization of amygdala-related networks that support emotional resilience and provide novel insights into how functional and neurochemical changes of the amygdala subregions contribute to adaptive emotional and cognitive functions in aging.